This is crap because of how misleading it is. For example yes a correlation exists between metabolic activity and lifespan across a wide range of life forms, but humans just like most birds are at the extreme edge.
So, as humans already have rather extreme lifespans relative to most organisms meaning our bodies are likely already using the low hanging fruit in terms of extending lifespans. But, without that context it seems like birds have some advantages we could copy.
This then hidden by first referencing a U shaped curve and ‘our place’ on it without clarifying it’s a metabolic curve not a lifespan curve.
Finally “In a 2007 analysis it was shown that, when modern statistical methods for correcting for the effects of body size and phylogeny are employed, metabolic rate does not correlate with longevity in mammals or birds.”
>“In a 2007 analysis it was shown that, when modern statistical methods for correcting for the effects of body size and phylogeny are employed, metabolic rate does not correlate with longevity in mammals or birds.”
Mitochondrial dysfuction comes primarily from manganese being replaced by iron, from the wrong Fe/Mn ratio (which the body has no way of correcting, as both are absorbed by the same mechanism and iron cannot be excreted.) or a deficiency in general, which results in mismetallation.
The general problem with iron is that while it is faster, it's also reactive in its free form, unlike manganese, which only works in proteins.
The majority of the world population is supposedly iron deficient, but the numbers are likely based on populations that already suffered from iron overload; it is possible that animal lifespans were substantially shortened as the result of human activity which disrupted the mineral balance to the degree no animal evloved to deal with.
IMHO longevity is overrated. I would put importance of fighting age-related diseases (including tissue aging, immune and hormonal decline in particular) well above extending longevity in importance. I certainly don't want to live 200 years looking and feeling what is considered adequate to being this old but looking and feeling like a 25-35-years-old until I reach something near the age of 60 (of course longer is kind of better perhaps but if I had to - this is what I'd trade) and die quickly and easily without going through even slightest form of disability (defined by comparison to healthy young adults) and physical struggle seems like something I'd totally buy into.
I'm curious how old you are. I don't think your opinion is at all uncommon, but it always seems to come from people that are young.
Life is really not that bad when you're old. Like, even when you're 60 there's a lot to live for. If I had to choose between living 40 years as a 40 year old or 25 years as a 25 year old it's not even close - I'd take being longevity at 40 in a heartbeat. Judging from how active my parents seem to be, I'd be happy to spend 100 years at retirement age too.
Given living standards in the West and thus the way we currently consume the Earth's resources, this planet cannot support everyone living to 80, let alone longer. Therefore surely better (in terms of the greater good) for us to live shorter lives, but full ones, free from disease/ageing/degeneration.
Maybe I'm misunderstanding you, but I think you're arguing that people dying means that the population is reduced? If so I think that's not the right conclusion.
If people lived longer, healthier lives they might delay having children or put off having children entirely. It is not true that countries with lower life expectancy have smaller family sizes. One of the reasons people have children is because it is a sort of immortality - they want their genes and family to be carried on. But if you actually live longer, that particular reason for having kids is weakened.
I don’t agree or disagree with you but apologize you are getting downvoted. I think multiple points of view are important for this topic especially, as contentious as they may be.
I want everyone else to be reasonable so I can game theoretically outsmart every one. If only there was a bigger player forcing us all to behave reasonable-like a state.
You probably are a citizen of a reasonably-social and well-developed country like Germany where getting old without having built a fortune does not imply doom of extreme poverty, alienation and rapid physical decay.
Lifespans depend on far more than just one thing, but multiple. Telomere shortening is a contributor, mitochondria may be, senescent cells, stem cell death, mechanical issues like joint or tooth wear down (partly coped in humans for now but very much an issue in other animals especially mammals which for some odd reason, in general don't have constantly regrowing teeth), etc etc.
But count we are really mitochondrians- a hundred times as many of them inside us as human cells. So human cells are really just vessels for mitochondria to make nore mitochondria with a bit of embelishment on the side.
>But if the conditions are unfavorable, if we’re starving, there’s a kind of switch from gearing up for sex and protein synthesis and bulking up to gearing up for survival: battening down the hatches and waiting out the bad times. This genetic switch has been the focus of most work on aging over the last decade or so.
Pure speculation, but based on its pervasiveness, I've wondered if depression could have been selected for through a mechanism such as this.
In my experience, reduced sex drive isn’t a terribly prominent symptom of depression.
Personally, I have always liked the idea of depression being a sort of strike. A social signal “baked into” genetics.
(Not that that interpretation has any more direct evidence. Maybe depression is just one of those bugs inevitable in billions of lines of self-modifying spaghetti code.)
>So if I focus all my resources on having sex, then effectively I take resources away from longevity. I take them away from surviving for longer, and so I shorten my lifespan almost deliberately in evolutionary terms.
This is a very interesting statement - in some of the Esoteric Teachings I have read throughout my life - they specifically say that masturbation for simple pleasure (ejaculation in males) -- drains you of your life essence and is seen spiritually as a selfish-wasteful use of your life - and this shortens your lifespan and reduces your spiritual power. (additionally, doing very deliberate things with sexual energy is a basis in sex magick)...
The idea being that you're pulling life-force from yourself and then 'projecting' intentionally toward what you're doing with that sexual energy -- which would be interesting if you were draining energy from mitochondria in general.
I think this line of thinking goes into an extreme. Preserving bodily fluids is not as useful as the Esoteric Teachings claim, and can lead to accumulation of frustration. They just keep people horny and try to reuse that energy, with more or less success.
Not vouching for it per se... I just get triggered by something that I read and then it brings up all the seemingly related content I have ingested in the past...
So, as humans already have rather extreme lifespans relative to most organisms meaning our bodies are likely already using the low hanging fruit in terms of extending lifespans. But, without that context it seems like birds have some advantages we could copy.
This then hidden by first referencing a U shaped curve and ‘our place’ on it without clarifying it’s a metabolic curve not a lifespan curve.
Finally “In a 2007 analysis it was shown that, when modern statistical methods for correcting for the effects of body size and phylogeny are employed, metabolic rate does not correlate with longevity in mammals or birds.”